Provide a wrapper for reset via watchdog

The watchdog register isn't in the same place, nor uses the same values
to trigger a reset.
Signed-off-by: Karl Palsson <karlp@tweak.net.au>

fel.c

@@ -1055,6 +1055,20 @@ void aw_rmr_request(feldev_handle *dev, uint32_t entry_point, bool aarch64)
 	pr_info(" done.\n");
 }
 
+/* Use the watchdog to simply reboot.  Useful to get out of fel without
+ * power cycling or plugging.
+ */
+void aw_wd_reset(feldev_handle *dev)
+{
+	const watchdog_info *wd = dev->soc_info->watchdog;
+	if (!wd) {
+		pr_error("No watchdog information available (yet) for soc: %s\n", dev->soc_info->name);
+		return;
+	}
+	fel_writel(dev, wd->reg_mode, wd->reg_mode_value);
+	pr_info("Requested watchdog reset\n");
+}
+
 /* check buffer for magic "#=uEnv", indicating uEnv.txt compatible format */
 static bool is_uEnv(void *buffer, size_t size)
 {
@@ -1164,6 +1178,7 @@ void usage(const char *cmd) {
 		"	dump address length		Binary memory dump\n"
 		"	exe[cute] address		Call function address\n"
 		"	reset64 address			RMR request for AArch64 warm boot\n"
+		"	wdreset				Reboot via watchdog\n"
 		"	memmove dest source size	Copy <size> bytes within device memory\n"
 		"	readl address			Read 32-bit value from device memory\n"
 		"	writel address value		Write 32-bit value to device memory\n"
@@ -1296,6 +1311,8 @@ int main(int argc, char **argv)
 			/* Cancel U-Boot autostart, and stop processing args */
 			uboot_autostart = false;
 			break;
+		} else if (strcmp(argv[1], "wdreset") == 0) {
+			aw_wd_reset(handle);
 		} else if (strncmp(argv[1], "ver", 3) == 0) {
 			aw_fel_print_version(handle);
 		} else if (strcmp(argv[1], "sid") == 0) {

soc_info.c

@@ -110,6 +110,16 @@ sram_swap_buffers h6_sram_swap_buffers[] = {
 	{ .size = 0 }  /* End of the table */
 };
 
+const watchdog_info wd_a10_compat = {
+	.reg_mode = 0x01C20C94,
+	.reg_mode_value = 3,
+};
+
+const watchdog_info wd_h3_compat = {
+	.reg_mode = 0x01C20Cb8,
+	.reg_mode_value = 1,
+};
+
 soc_info_t soc_info_table[] = {
 	{
 		.soc_id       = 0x1623, /* Allwinner A10 */
@@ -119,6 +129,7 @@ soc_info_t soc_info_table[] = {
 		.swap_buffers = a10_a13_a20_sram_swap_buffers,
 		.needs_l2en   = true,
 		.sid_base     = 0x01C23800,
+		.watchdog     = &wd_a10_compat,
 	},{
 		.soc_id       = 0x1625, /* Allwinner A10s, A13, R8 */
 		.name         = "A13",
@@ -195,6 +206,7 @@ soc_info_t soc_info_table[] = {
 		.sid_fix      = true,
 		/* Check L.NOP in the OpenRISC reset vector */
 		.needs_smc_workaround_if_zero_word_at_addr = 0x40004,
+		.watchdog     = &wd_h3_compat,
 	},{
 		.soc_id       = 0x1681, /* Allwinner V3s */
 		.name         = "V3s",
@@ -215,6 +227,7 @@ soc_info_t soc_info_table[] = {
 		.rvbar_reg    = 0x017000A0,
 		/* Check L.NOP in the OpenRISC reset vector */
 		.needs_smc_workaround_if_zero_word_at_addr = 0x40004,
+		.watchdog     = &wd_h3_compat,
 	},{
 		.soc_id       = 0x1701, /* Allwinner R40 */
 		.name         = "R40",

soc_info.h

@@ -51,6 +51,16 @@ typedef struct {
 	uint32_t size; /* buffer size */
 } sram_swap_buffers;
 
+/*
+ * Contains information on the watchdog peripheral, to enable reset
+ */
+typedef struct {
+	/* Register that needs to be written to */
+	uint32_t reg_mode;
+	/* Value to write to trigger a reset */
+	uint32_t reg_mode_value;
+} watchdog_info;
+
 /*
  * Each SoC variant may have its own list of memory buffers to be exchanged
  * and the information about the placement of the thunk code, which handles
@@ -101,6 +111,7 @@ typedef struct {
 	uint32_t           sid_base;     /* base address for SID registers */
 	uint32_t           sid_offset;   /* offset for SID_KEY[0-3], "root key" */
 	uint32_t           rvbar_reg;    /* MMIO address of RVBARADDR0_L register */
+	const watchdog_info *watchdog;   /* Used for reset */
 	bool               sid_fix;      /* Use SID workaround (read via register) */
 	/* Use SMC workaround (enter secure mode) if can't read from this address */
 	uint32_t           needs_smc_workaround_if_zero_word_at_addr;